Endocrine Abstracts

Heparin is being frequently used in most hospitals within the U.K. The use of low molecular weight heparin is increasing also amongst different specialities. The risk of bleeding and thrombocytopaenia with heparin treatment is well recognised. However other side effects of heparin therapy like hyperkalaemia, which can be life threatening due to the high risk of arrhythmias are less commonly perceived.

We describe a 59 year old female patient with type 2 diabetes, hypertension, peripheral vascular disease and previous left above knee amputation, who was admitted with a swollen right calf and right heel ulcer. She was suspected to have deep vein thrombosis as well as possibly cellulitis around the heel ulcer on the same leg, and she was treated with 13,000 units of Tinzaparin daily (based on her weight of 75kgs) along with intravenous antibiotics. Her other medications prior to admission included Alendronate 70mg once weekly, Calcichew 2 tablets once daily, Lansoprazole 15mg once daily, Amiloride 5mg once daily, Ferrous sulphate 200mg once daily, Furosemide 40mg twice daily, Aspirin 75mg once daily, and Human Insulatard 8 units once daily. She was not on non-steroidal anti-inflammatory drugs. Biochemical profile was done on admission and blood tests were not done for the next two days. On the third day after admission the lab phoned through her serum potassium concentration (6.5mmol/l) and hence the Amiloride (which she was on long term) was stopped. Despite this initial measure, the serum potassium concentrations continued to rise again. This started to fall only two days after the treatment with Tinzaparin was stopped, and remained within the reference range thereafter off the heparin therapy. Heparin-induced hyperkalemia, is caused by an enzymatic block in the synthesis of aldosterone. However, in most cases severe hyperkalemia occurs in the presence of additional factors influencing potassium homeostasis.